Compressor unit



ream d Jan. 24, 1939 UNITED STATES PATENT OFFICE COMPRESSOR UNIT Jens A. Paasche, Wilmette, in. Application April 30, 1937, Serial No. 139,897

-9 Claims- (01130- 171) The invention relates generallyto compressor units or the like and more particularly to that type of unit which utilizes a flexible diaphragm as the means'for applying-a compression force.

, An object of the invention is to provide a .unit of this character which'is of simple construction, for easy assembly, has relatively few moving parts, and in operation is exceedingly quiet and eflicient.

Another object of the invention is to provide a unitin whichthe diaphragm itself is utilized in a noveland effective manner as a means for valving or controlling the flow ,of fluid through the unit. I

More specifically stated, another object is to provide an improved compressor unit which embodies a casing-having an internal partition arranged to cooperate with a movable diaphragm to place a fluid under pressure,'and driving means for the diaphragm which is so correlated with one or more flow apertures in the diaphragm as to control the'flow of fluid into the space between the partition and diaphragm with high efflciency.,

Other objects and advantages will become apparent in the following description and from the accompanying drawing, in which:

Figure 1 is a view of acompressor unit embodylng the features of the invention, the unit being shown in vertical central section.

Fig. 2 is a view similar to Fig. 1, but illustrates a different position of the operating mechanism.

- Fig. 3 is a plan view of a diaphragm.

' While the invention is susceptible of various modifications and alternative, constructions, I have shown in the drawing and will herein describe in detail the preferred embodiment, but it is to be understood that I do not therebyim tend to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention-as expressed in the'appended claims.

With particular reference to Fig. 1, I designates generally a hollow casing which, in the present instance, is, illustrated as being an upright,-somewhat elongated dome-like structure formed of two horizontally divided parts, namely an upper section H and a lower section l2. These sections are interfitting and are adapted to be suitably secured together. Inthis embodiment, the casing 'is supported by attaching its lower section to the housing of a driving motor I 3, the armature H of which is arranged to extend into the interior of the lower section.

Internally of the lower section, and spaced 9. short distance inwardly from its open face, is a shoulder l5 adapted to receive the marginal or peripheral portion of av flexible diaphragm l6 formed of a suitable material, such as rubber, 5 leather or-the like. The end face of the upper casing section has an axially concentric flange ll projecting therefrom and adapted, when the casing sections are assembled, to abut the outer face of the diaphragm and bind it against the shoulder 15. The flange I! has an inwardly facing rabbetted groove l8 to receive the peripheral portion ,of apartition or wall I 9 and binds the wall rigidly in place when the sections 'are assembled. Preferably, the face of the wall, 16

which opposes the diaphragm, is concave.

' a disk of substantial diameter adjacent to and underlying the diaphragm IS. The diaphragm opposing face of the head is convex substantially complemental to the concave surface of the partition 19, and the parts are so arranged that when the head is in its uppermost position, there is very little or no space between the head, the diaphragm and the partition.

' I Centrally, the face 25 is arcuately depressed, as

at 26, to provide an annular peak 21 or high point on the face of the head disposed concentrically of and relatively close to the axis. The d'aphragm follows the surface contour of theface into the depression, and such means as a screw 28, passing through the head and into 40 screw threaded engagement with the connecting rod on the axis of the assembly, unites the dia-' phragm, head and connecting rod. Preferably, a washer 29 or the like is interposed between the head of the screw and the diaphragm, and this washer may be of substantial diameter to bind the diaphragm against the head at a point relatively close to the peak 21. The .diaphragm is apertured in substantial opposition to the high point on the head and, in this instance, a plurality of apertures 30 (Fig.3), arranged in gen erally circular series axially of the assembly, is employed. I

In operation, and considering that the parts are in the relationship assumed at the end of the compression stroke, as shown in Fig.1, movement 01 the head downwardly results in a gradual separation of the diaphragm from the head-due to the convex surface of the head. Because of the relationship between the apertures in the diaphragm and the high point on the head, it will be evident that when the head reaches the end 0! its reciprocatory stroke more remote irom the partition, the apertures will be open permitting an inflow of fluid to the space between the diaphragm and the partition as indicated by the arrows in Fig. 2. Immediately upon the start of the compression stroke, the high point on the head moves into closing relation to the diaphragm apertures, thus trapping the fluid between the diaphragm and the partition without lost motion and without permitting theescape 01' any of the trapped fluid. As the compression stroke proceeds, fluid between the diaphragm and partition is placed under pressure and allowed to escape through a port 3! in the partition which is controlled by a check valve 32 mounted in a valve housing 33 carried axially by the partition. The convex and concave relationship oi the head and partition insures that the full energy of the compression stroke will be utilized to expel all of the fluid from the space between the diaphragm and the partition.

In the present embodiment, in which the compressor unit is of the type adapted for placing air under pressure, intake of air to the low pressure side-o1 the diaphragm is through an aperture 34 formed in the lower casing section opposite to the crank shaft assembly. Preferably the aperture is covered by a suitable air filter 35 of felt or the like. The outlet for compressed fluid is through a passageway 36 communicating through the upper casing section with the high pressure side of the diaphragm. a

It will be evident from the foregoing that a novel compressor unit has been provided which is quite simple in construction and may be manu factured and sold at a relativelylow cost. All of the parts are constructed and arranged for convenient and rapid assembly and are quickly available for inspection and repair. The unit is highly efllcient in operation, since all of the pressure fluid which is drawn into the space between the diaphragm and the partition is trapped therein without loss of fluid immediately the compression stroke starts and all of the trapped fluid is expelled from said space. The general arrangement of the various elements constituting the unit and, in particular, the disposition of the flxed partition within the casing produces a unit which is exceedingly quiet in operation.

I claim as my invention:

1. A compressor for air or other fluids comprising, in combination, a hollow casing composed of a pair of complementary sections, a concave partition extending across the interior of said casing and peripherally supported between said sections, a flexible diaphragm disposed on the concave side oisaid partition and peripherally secured between said sections, a disk-like head on the side of said diaphragm opposite said partition having a. convex face substantially the complement of the concave partition, means for securing said diaphragm substantially axially to said head, means for reciprocating said head to move said diaphragm toward and away from said partition, said diaphragm having a plurality of apertures therein arranged substantially concentrically about the securing means, said apertures being disposed closely adjacent to said securing means in that part of the diaphragm which separates only a short distance from the head during the last portion of head movement away from said partition, whereby the apertures serve as valve ports and are only open substantially at the remote transition point of the head relative to the partition, inlet and outlet openings in the casing on the head and partition sides oi the diaphragm respectively, and a check valve carried by the partition arranged to permit a flow only from the space between the diaphragm and partition.

2. A compressor for air or other fluids comprising, in combination, a hollow casing, a concave partition extending across the interior of said casing, a peripherally supported flexible diaphragm disposed on the concave side of said partion, a head of substantial size on the side of said diaphragm opposite said partition having a convex face substantially the'complement of the concave partition, means for securing said diaphragm centrallyto said head, means for reciprocating said head to move said diaphragm toward and away from said partition, said diaphragm having a plurality of apertures therein disposed closely adjacent to said securing means to be closed by abutment with said head during the major portion of a reciprocatory stroke and to be open 'only during movement of the head through its transition point remote from the partition, inlet and outlet openings in the casing on the head and partition sides of the diaphragm respectively, and a check valve carried by the partition arranged to permit a flow only from the space between the diaphragm and partition.

3. A compressor iior air or other fluids comprising, in combination, a hollow casing, a parti tion extending across the interior of said casing, a peripherally supported diaphragm disposed adjacent to said partition, a head on the side of said diaphragm opposite said partition having a convex tace, means for securing said diaphragm substantially centrally to said head, means for reciprocating said head to move said diaphragm toward and away from said partition, said diaphragm being apertured closely adjacent to said securing means for cooperation with underlying portions of said convex face to provide a valve action controllingthe admission of fluid to the space between the diaphragm and partition, said convex face being shaped to permit of aperture exposing separation of the diaphragm therefrom substantially only at the remote transition point of the head relative to the partition, inlet and outlet openings in the casing on the head and partition sides of the diaphragm respectively, and a check valve arranged to permit a flow only from the space between the diaphragm and partition. 4. In a compressor unit, the combination 0! a hollow casing having a fixed partition therein and a reciprocatory head opposing said partition, a diaphragm interposed between said head and partition, means connecting said diaphragm substantially centrally with said' head, said diaphragm being apertured to permit of a flow of fluid therethrough, said head having a convex face opposing said diaphragm arranged in the reciprocation oi the head to occupya spaced relation to the apertured portion 0! the "diaphragm only when the head is remote from the partition, and passageways ior allowing fluid to flow through said casing including a check valve for preventing a return flow through the partition into the space between the diaphragm and partition.

5. In a compressor unit of the character described, the combination of a hollow casing having a transversely extending diaphragm therein dividing the easing into low pressure and high pressure sides, a fixed wall on the high pressure side of and adjoining said diaphragm and having a check valve thereon permitting a flow through the partition away from said diaphragm, and a reciprocatory head secured to said diaphragm on the low pressure side thereof, said diaphragm being apertured within the peripheral outline of said head for coaction with said head to open the apertures while said head moves away from said wall and close said apertures upon reverse movement of the head.

6. In a compressor unit of the character described, the combination of a hollow casing having a transversely extending diaphragm therein, a reciprocatory head having a diaphragm opposing face which is generally convex and has an axial depression providing an annular peak adjacent to the axis thereof, means for securing said diaphragm to said head with the diaphragm axially turned into the depression, said diaphragm being apertured in opposition to the peak so that the passage therethrough provided when the head is drawn away from the diaphragm is closed immediately upon initial movement of the head toward the diaphragm,.and means for trapping the pressure fluid created by the movement of the diaphragm after the head has closed the aperture therein.

7. In a compressor unit of the character described, the combination of a hollow casing having a transversely extending diaphragm therein, a reciprocatory head having a diaphragm opposing face provided with a substantially annular a flow therethrough high portion, means for securing said diaphragm to said head to permit the diaphragm to follow the contour of said face, said diaphragm having apertures disposed to oppose said high portion so that fluid flow through said apertures is possible only when the head is drawn away from the diaphragm, said high portion being arranged to engage said diaphragm and close said apertures upon initial movement of the head toward the diaphragm, and means for trapping the pressure fluid created by the movement of the diaphragm after the head has closed the apertures therein.

8. In a compressor unit, the combination which includes a flexible diaphragm, a. housing therefor having means for peripherally supporting said diaphragm, a reciprocatory member, and means for connecting said diaphragm to said member. said diaphragm having at least one aperture therein to permit a flow of fluid therethrough, said member having a high point in opposition to an aperture for cooperation therewith to prevent except substantially in one extreme position of reciprocation.

9. In a compressor unit of the reciprocatory flexible diaphragm type, the combination of a flexible diaphragm apertured to permit a flow of fluid therethrough, and means for imparting reciprocatory movement to said diaphragm including a member having a surface adjoining the apertured part of said diaphragm andshaped for closing association therewith to prevent said flow except when said means is substantially at the point of transition from intake stroke to pressure stroke.

JENS A. PAASCHE. 

